By

Used to indicate the person that does something in a passive voice sentence:

The microwave was fixed by the mechanic.

The flowers were delivered by a postman.

The branch office was closed by the head office.

Used to indicate an action with a particular purpose:

You can pass the exam by preparing for it.

I expressed my feeling toward her by writing a letter.

She finally broke the record by pure effort.

Used to indicate a mean or method:

Please send this package to Russia by airmail.

I came here by subway.

[Quiz 24.1]

Choose the correct preposition in each sentence.

1)If she left at 4 p.m., she should be here (with, over, by) now.2)Go (with, over, by) there and catch my ball. 3) (With, Over, By) your determination, you will be able to achieve your dream. 4)I just found it! It was (with, over, by) the radio on my desk. 5)I knocked him (with, over, by) accidentally. 6)She was (with, over, by) me when the accident occurred.